1. Field of the Invention
The present invention relates to copYing apparatus and particularly to a copying apparatus for optically scanning an original, forming, on a photoconductor, an optical image of the original of a magnitude variable according to a set copying magnification, and transferring the optical image onto paper.
2. Description of the Prior Art
Copying apparatus having a so-called one-sided binding or blank margin mode for making a copy with a margin of 5 mm, 10 mm or 15 mm for example on one side edge of paper is well known.
FIG. 1 shows an example in which an original is copied in the one-sided binding or blank margin mode.
In FIG. 1, the left illustration shows a size of an original to be copied and the right illustration shows a copy of the original (the hatched area corresponding to the original). In this example, a scaled-down magnification is applied to an optical image of the original and timing for transferring the image is delayed, whereby a blank space for binding is formed on one side of the copy paper as shown in the right illustration.
Thus, a margin for binding in the conventional binding margin mode is formed only on one side edge of paper. Let us assume for example that a document of the A4 size is copied in the binding margin mode and that the copies thus obtained are filed in the A4 size. In this case, if the two facing pages of the filed copies are opened, either of the pages is blank, that is, a back face of the copy. In order to avoid this inconvenience, some users desire to make copies of the A3 size, to fold each copy in two and to file the folded copies in the A4 size.
FIG. 2 shows an example in which an original is copied in a both-sided binding margin mode so as to be folded for filing.
In FIG. 2, the left illustration shows a size of the original to be copied and the right illustration shows a copied state (the hatched area corresponding to the original). Thus, after filing of the copies obtained in the both-sided binding margin mode, both of the two opposing pages to be opened are copy faces and the filed document is convenient to use.